It has long been recognized that it is advantageous to protect animals from insect pests and parasites. Perhaps the first method of protecting the animals was to manually spray insecticide on the animals. A later method of controlling the insects was to hang oily burlap sacks or the like from some sort of support so that the animals could rub against the same. A later apparatus for controlling the insects was the so-called "cattle oiler" against which the cattle could rub with the rubbing action transferring the oil and/or liquid insecticide onto the hair and coats of the animals.
In an attempt to eliminate some of the problems associated with the prior art devices, applicant devised an insecticide applicator which was the subject of U.S. Pat. No. 3,913,530. In the applicator of the '530 patent, a flexible tube is supported between a pair of supports with a bag of insecticide dust being supported adjacent one end of the tube with the contents of the bag being in communication with the interior of the tube. When the dust bag becomes empty, a replacement bag is substituted therefor. Although the applicator of the '530 patent has met with considerable success, it has been found that the shipment of the dust bags poses a problem. A further problem associated with the applicator of the '530 patent is in the procedure for replacing the dust bag. Yet another problem of the '530 device is the cost of the support stand for the dust applicator.